| Research Abstract |
There are trace amounts of bioactive substances such as carboxylic acids, alcohols, and amines in the body. The determination of them is quite significant for elucidation of physiological function, diagnosis of sickness, explication of cause of disease, and medical treatment. Therefore, many fluorescence derivatization reagents have been developed for the determination of these substances by high-performance liquid chromatography (HPLS). In this project, I investigated new fluorescent 6-aminoquinoxalines and their application to fluorescence derivatization reagents for carboxylic acids.
1.2,3-Disubstituted 6-nitroquinoxalines were obtained by treatment of 2,3-dichloro-6-nitroquinoxaline with some nucleophiles such as amine, alcochol, and crown ether in high yields. 2. The catalytic hydrogenation with 10% Pd-C afforded fluorescent 6-aminoquinoxalines. 3.6-Aminoquinoxalines were coupled with long-chain carboxylic acids by means of the dicyclohexylcarbodiimide (DCC)-1-hydroxybenzotriazol (HOBt) method t give the corresponding 6- (acyl) aminoquinoxalines. 4.6- (Acyl) aminoquinoxalines were monitored by reversed phase HPLC equipped with a fluorescence detector (lambdaex 330 nm, lambdaem 395 nm) by using a column packed with a Finepak SIL C_<12>S.5. All the peaks were completely separated within 40 min. 6. The detection limit of these N-acyl derivatives were found to be 1.0 fmol/mul (injection volume).
In conclusion, 2,3-disubstituted 6-aminoquinoxalines have been demonstrated to be applicable to new fluorescence derivatization reagents for the carboxylic acids.
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